This invention relates to a cup for holding an ingredient for a drink and is principally concerned with thin walled cups of plastics material, a number of which may be nested together in a stack with a space being provided between the base of one cup in the stack and the next adjacent cup, which space may contain an ingredient in powdered form, for example. British Patent Specification No. 1,395,026 discloses such a cup. There are several requirements which have to be met in order to provide a useful article.
It is required to provide a seal above the ingredients contained in the one cup and which prevents the fine powders from contaminating the outer side walls of the other cup and prevents, at least to a substantial extent, the ingress of moisture and other contaminants from the atmosphere. It is also required to keep the faces forming the seal in contact during handling and for two adjacent cups to be retained so that a stack thereof does not become disassembled.
As each cup in the stack may contain upwards of twenty grammes of ingredients within the base then a stack of forty cups, as example, could weigh over eight hundred grammes and it is necessary to include a feature which reduces the tendency of the cups in the stack to jam or "telescope" together when subjected to axial shock loads such as being dropped or otherwise mishandled. It will also be understood that when the stack of cups is assembled into a vending machine then there must be a constant and pre-defined characteristic to the detachment of the lowermost cup from the stack.